Pneumatic shock absorber



Jam. 11,4944.

B. BOULOGNE ET AL PNEUMATIC SHCK ABRORBER Filed Oct. l2, 1940 2 Sheets-Sheel.

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Jan. 11, 1944. BQBOULOGNE ETAL PNEUMATIC SHOCK ABRORBER 2 Sheets-Sheet 2 Fi'led Oct. 12, 1940 l 0f Fig. 2.

A asomewhat difterent construction,

.Qrfthe apeararfsf hereinater 150.302. ,celled the zfipeerer Patented Jan. 11, 1944 Pengalengajnanear Bandoeng, Java, Nether- .,land Eastlndes; v.vestedin theAlien Property Custodian Application yOctober 12., 1940,.seria1No.- 361,007

' IntheNetherlands.MayA 11,' 1940 Thisinvention Arelatesto pneumaticzshock aby sorbers flor automobiles andother vehicles.

i Apparatus such as pneumatic shock absorbers .-,ha'v'e been announced under: U. .SQPatent` No. l,5i4,850,Messier and several others, but. have not come into usefwhichfshowsthat although `=there has for a long time been great interestin this subject, an equipment meeting4 .practical regulrements has not yetl been found.

yAccordiz-ig tothisinvention, the desired degree ci. .usefulness can be attained bythe application of, an -air cushion arrangement of the kind as herein'afterl described, examples of v.which are.- given in the accompanying drawings, Figs. l to 8,1,.inelusive. 1

g'Fig. 1 is a vertical section along Vthe line I-I Eig. 2\is atop View. t Fig'. 3-is a vertical section on line 3-3-.with the `.piston illustrated in elevation.

- Fig.--is avertical sectionsimilar to Fig. 3 on linIL-ll, b utYWith-the piston andY inner cylinder removed.

-Fig.l5-is ahorizontal section on line 5-5 vof "MF-1.2% 4f W@Fier 6 is a horizontal sectionon line iS--Bpf' LeFig: 3.

"IA is a top view ofthe piston. .Figf Bshows parts-ot a piston -andvcylinder .of

--This shockabsorber is so constructed that dur-c Y-far away from the cylinder top and does not 1. knock againstv the bottompf the cylinder. Fur- -th'errnoray the voperation of Athe'apparatus is such that when; applied .te anfadomobnethe quantity of air forming the fair-cushion is-maintainedeven `when passengers leave-the car for a short-vv'hi1e."" The quantlty of -air only comes into conformity vwith thedecreased load (Without any knocking voff-the piston) `if the car should proceed empty.

'f-Furthermore, whendriving' on uneven ,roadstheux d iubricating matter on-the piston, Will not yescapel vin-its entirety Withfthedischarge of air .Lsimple'forniof construction can be applied. The apparatus consistsot av cylinder I containing in-lt a piston 2, and operates as'ollowsz- In4 kThe .quantity of air inthe bearer (supply and ldischarge) Vis regulated `bythe position of the pis- .ton in the. cylinder.

The supply of air to the ..bearers;.may,f. for. example, be from a pump or if desired from .an interposed supplyreservoir. Ii in chamber 3 there :,is' .not sufficient air pressure .to bear the. weight .of the.. car, the kpiston .Will be pushedtoWard. and. substantially. into vcontact with the...cylinder.,top bythe cars Weight and compressed air will thenpass. in the; direction ot the arrow .through the canal il. Thevalve 5 will then be opened .and this air will reach .the -annular groove 6 .in the inner. Wall of the cylinder Y through channel. Sandport 5b .and from there flow intothe groove. 'l of the. piston. .When the piston is..pushed.against.the cylinder topthe aforesaid grooves 6 and 1 communicate with each other and also .withithetshora axially-extending groove 8. `.This short. groove 8,.by means of the annular Vgroove 9 inzthe cylinder, gives access to lone of thesmall groovesiUJin the piston, sothat `.this groove y,Ill `thus gets filledr with, compressed air kThis air'then vcontinues its passage through an adjacent-groove 9 .inthe cylinder and a small groove.y i0 inthe piston, and ilnally reaches the short grooves iLvvhencethe air passes through canal -I2 into .the chamber 3. Inthis chamber the'compressedair `pushesthe ypistonin the cyl- .indendownwari.andtheweight,of the car is 'borne lbythe air cushion being iormed.- The supply of compressedairto the chamber 3 stops as soon as theshort. grooves I Ihave passed groove 6 `due tothe .downwardtmovement of the piston i in the cylinder.

f Lubricating m'attere-hereinafter` to. be called oil'-can be lsuppliedto chamber. 3. and to the piston feither'with-.the compressed. air or separately.' vAsthe `piston does.. not remain -in the fsame place in thecylinder. during a journey, its

movementswill repeatedly establish communica- U'tin between `groot/esti and E and, consequently,

Y it Willassume alsomewhat lower average position. 'Eachz tin'ieftlleshort. grooves .il reachthe groove -|3, which goes` over. the .entire .circumference of the-cylinder, lair. from. chamber 3 Will escape through -ffl '2, :I l .and vI 3 `into chamber YI d, .and any *excess of.oil on'the piston YWiIlalSo .be drawn j-along and, blown'in Vthat directionfthrough the 'canal lgvserve vfor. lubrication of` the tube..'|6,

V'the cylinder y; chamber 3 there isA maintained a f cushion of'rcom'prefssed air andV the pressure'ther'eso that leakage along` thistubefis prevented.- The average' position of the ypiston 2 in the cylinder l if Willtljien be-as shovvn approximately in the Y drawings-between the point Where contact between theshort groove Il andthe groove 6 is ....551 Lenten). .e114 'Pee wie# Where. @Detect is.. mede between the short groove II and the groove I3. Ii? during travel the piston going downward moves so far in the cylinder that the short grooves II pass groove I3 completely and these small grooves are thereby covered, some air will again be let out of chamber 3 as soon as the short grooves il, going farther downward, reach groove I'I.

The arrangement can also be effected in such a manner that discharge of air from 3 can only take place when II communicates with I3, While discharge may also be made to take place through, for instance, more than two consecutive grooves and divided over several periods of time. The groove il not extending over the entire circumference of the cylinder, as shown in Fig. 6,

prevents openings I8 and I9 from communicating with each other in any other way than n through the groove I made for that purpose in the piston, In view of this break in the groove Il the two short grooves II in the piston are offset from one another axially of the piston, so that contact with Il is insured by at least one of these two short grooves. If desired, suitable means may be employed to prevent the piston from turning during its operation.

The air and oil in chamber I4 are pumped out bythe upward and downward movement of the piston, and in order to prevent leakage of oil along tube I5 the average pressure maintained in this chamber is preferably somewh-at lower than atmospheric pressure. This pressure in chamber i4 can as desired be regulated by various means. The method used here to maintain an average pressure in chamber I4 lower than atmospheric pressure is as follows: When air and oil have entered chamber I4 during the downward movement of the piston, the pressure thus caused here will escape through the opening I8 as soon as the piston in its upward movement uncovers this opening. When the piston again moves downward this opening is again covered, and the pressure in I4 increases somewhat; consequently, when the groove 'I around the piston connects opening I3 (which opening is equipped" with a non-return` valve |80., Fig. 3) with the opening l some air will again escape from cham ber it through the opening I8, valve I8a, canal Eto to discharge outlet I8c and will draw along with it some oil out of I4. vWhen the piston moves downward and the opening I8 has been covered, its further descent causes compression in chamber I4 and knocking of the piston against the bottom of this chamber is therebyA prevented. Moreover, chamber 20, for example, canfun-ction either in conjunction with chamber I4 or independently, instead of it, while if desired other chambers can be made to replace or Yco-operate with one or both of the aforesaid chambers by adopting a different form of construction,

As shown in the example, Fig. 8, the opening i8 and Illa can be so located thattheyfcannot be connected to each other by the groover'l, which groove can then be differently shaped and be, for instance, larger. The pumping from chamber I4 then takes place as follows: When after an upward movement of the piston` (whereby the opening i3 is uncovered and discharge has taken place from I4) the opening I8 isagain covered by the downward movement of the piston, presY sure will he created in I4 by the piston going farther downward. Thus as soon as .'I comes Y into contact withopening I9 this groove I will be filled with air and oil flowing in there from le, and when in the following upward movementf.

ing I8, the contents of this groove being under some pressure a part of it will flow into the opening I8.

A greater part of the weight of a car will be borne by the rear axle when driving uphill than on a horizontal road, and the air cushions in the rear `bearers will then consequently be more depressed. 'Ihe `air supply then automatically comes into operation and more air enters into chambers 3 of these bearers. The front bearers, however, will have less weight to carry when driving uphill, and if the load be considerably decreased apart of the compressed air will be al lowed to escape from these bearers into chambers I4'. When the pistons have come sufliciently downward below their middle position in the cylinder, the opening I8 will be covered, so that the air allowed into chamber I4 cannot escape but will press against the lower end of the pism tons, thereby preventing their knocking against the bottom of the cylinders. When driving down a hill the air in the chambers I4 of the rear bearers will act in the same way.y In a similar Vmanner the apparatus helps to keep the carin a horizontal position when making a turn. During a somewhat long climb or descentthe air cushions in the bearers automatically adjust themselves to their load inthe same way as takes place on Ia horizontal road. If from a fully loaded car equipped with shock-absorbers, as above described, all passengers get out at the same time, whereby the quantity of air in the bearers is no longer in conformity with theweight of the empty car, the pistons 2 will assumeV such a low position in the cylinders I that air flows from chambers 3 into the chambers I4 until this air in these chambers Ill, pressing against the lower end of the pistons, has again brought the latter so high up in the cylinders that the small grooves II are no longer in communication with the groove i3. Especially in the case of Fig. 8, there can be no discharge from I4 through I8 unless the pistons move up and down; therefore, if the car is not riding no air will escape from the bearers. If now the passengers get into the c-ar again, the air present in the bearers is still in conformity with the weight of the loaded car. Should the car drive off empty, the movement of the pistons will cause a repeated discharge of air from chamber I4 through I8, 'and the air-filling in the bearers will in a short time be in conformity with the weight of the empty car. Should a number of passengers now get into the car, the air-lling in the bearers will not be suificient to carry the loaded car, but replenishment will take place very quickly, because as long as the air-filling in the bearers is insuli cient the pistons in the cylinders nd themselves in such fa position that the supplyof aire-which for the purpose of quick replenishment vmay be effected from a reservoirtakes place withoutinterruption. Y

The compressed air in chamber 3 of the cylinder I will, if a wheel of the car goes over a raised spot (bump) in the road, be further compressed and partly driven out through the opening' ZI. When the piston in its movement further upward covers the opening 2 I only the air shut up in -the upper part of the cylinder will be further 'com pressed, the pressure of which then quicklyicreases and prevents the piston from Vknocking against the top of the cylinder. Theopeningf'l is in communication with an Vair chamber whose size determines the degree of resiliency of. the apparatus. The height of the small pipAe`A2'2 determines the thickness of the `oil layer on the piston. The grooves 9 in the cylinder are-of great importance to the sealing off and lubrication of the piston when it is in its middle position. In order to decrease the possibility of leakage of oil along the tube I6, one or more grooves 23, with or without oil outlet holes, canV be made in the inner wall of the piston 2 which slides over this tube I6. The air discharge from chamber 3 can, if desired, be so led that a part of this discharged air enters chamber I4, while another part of it follows another path.

Compressed air c-an be obtained from, for instance, a motor-driven pump, wherewith under inuence of the difference between the pressure in the delivery piping and that in the suction piping of said pump, the inlet to the suction piping is automatically shut 01T by a sliding valve, or other such device, as soon as the desired pressure has been reached.

A spring device can, if desired, be placed between the upper cover of the cylinder and the top of piston 2, or in some other place and manner, so that in case the bearer should contain insufcient air the car can ride on and be supported by such spring device.

It is also evident that Various changes, modifications, variations and substitutions might be resorted to without departing from the spirit and scope of the invention.

We claim:

l. A pneumatic spring device for vehicles, comprising a cylinder and a piston slidably arranged therein, one of said elements being connected to the vehicle body and the other to a lower supporting body, one end of said piston being spaced from the corresponding end of said cylinder to form a cushion chamber containing a gas under pressure, the other end of said piston being spaced from `a wall at the other end of said cylinder to iorm an auxiliary chamber, a channel in said piston communicating with said cushion chamber and with a port in the side wall of said piston, a channel in the Wall of said cylinder communicating with said auxiliary chamber and with .a port in the side wall of said cylinder, said ports being adapted to register to establish connection between said cushion chamber and said auxiliary chamber in a rst relative position of said cylinder and piston and to cut off communication therebetween in other positions, an outlet from said auxiliary chamber controlled by a nonreturn valve and communicating with a port in the side wall of said cylinder, and a conduit in said piston adapted in a second relative position of said piston and said cylinder to establish communication between the port communicating with said auxiliary chamber and the port communicating with said outlet, whereby as the end of said piston nieves away from the end oi said cylinder to enlarge the main chamber the discharge of gas from the auxiiiary chamber is shut off before communication is established between said cushion chamber and said auxiliary chamber.

2. A pneumatic spring device for vehicles, comprising a cylinder and a piston slidably arranged therein, one of said elements being connected to the vehicle body and the other to a lower supporting body, one end of said piston being spaced from the corresponding end of the cylinder to form a cushion chamber containing gas under pressure that supports the vehicle body, the other end of said lpiston being spaced from a Wall at the other end of said cylinder to form an auxiliary chamber, means establishing communication' between said cushion chamber and said auxiliary chamber in one relative position ofsaid cylinder and piston and cutting off such communication in other positions, means comprising cooperating ports in said piston and cylinder for venting said auxiliary chamber to an outlet in a relative position of said cylinder and piston spaced from the position in which communication is established between said cushion chamber and said auxiliary chamber.

3. A pneumatic spring device for vehicles, comprising a cylinder and a piston slidably arranged therein, one of said elements being connected to the vehicle body and the other to a lower sufpporting body, one end of said piston being spaced from the corresponding end of the -cylinder to form a cushion chamber containing g-as under pressure that supports the vehicle body, the other end of said piston being spaced from a wall at the other end of said cylinder to form an auxiliary chamber, means admitting entry of lubricating matter to said cushion chamber, means connecting said cushion chamber to said auxiliary chamber in one relative position of said cylinder and piston to discharge lubricating matter and gas from said cushion chamber, valve means controlled by relative movement of said cylinder land said piston to discharge gas from said auxiliary chamber to `an outlet at one relative position of said cylinder and piston, said valve means being closed when said cylinder and piston are in such relative 'position as to establish connection from said cushion chamber to said auxiliary chamber.

4. A pneumatic spring device for vehicles, comprising a cylinder and a piston slidably arranged therein, one of said elements being connected to the vehicle body and the other to a lower supporting body, one end of said piston being spaced from the corresponding end of the cylinder to form a cushion chamber containing gas under pressure that supports the vehicle body, the other end of said piston being spaced from a Wall at the other end of said cylinder to form an auxiliary chamber, .a channel in said piston opening into said cushion chamber above the level of the surface of said piston, whereby a layer of lubricating matter will be retained on said surface, said channel communicating with a port in the wall of said piston, said cylinder having a channelcommunicating with said auxiliary chamber and with a port in said cylinder registering in a first relative position of said cylinder and piston with the port in said piston, said cylinder having an outlet port connected to said auxiliary chamber in a second relative position of said cylinder and piston spaced from said first position, whereby upon relative movement of said cylinder and piston to decrease the volume of said cushion chamber connection of said auxiliary chamber to said outlet port is shut off before communication from said cushion chamber to said auxiliary chamber is established.

5. A pneumatic spring device for vehicles, comprising a cylinder and a piston slidably arranged therein, one of said elements being connected to the vehicle body and the other to a lower supporting body, one end of said piston being spaced from the corresponding end of the cylinder to form a cushion chamber containing gas under pressure that supports the vehicle body, the other end of said piston being spaced from a wall at the other end of said cylinder to form an auxiliary chamber, channels in said cylinder and said iiiary chamber to an outlet in a second relative position of said cylinder and piston, said ports registering intermittently upon repeated relative movement between said cylinder and piston to 5 vary the pressure in said auxiliary chamber.

BALTUS BOULOGNE. .ANTONIE PIETER BOULOGNE. 

